This application claims the priority of German application 199 49 080.5, filed in Germany on Oct. 12, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a fixing device for an injection nozzle, in particular, for internal combustion engines with direct fuel injection. The injection nozzle is of the type having a nozzle holder body whose cylindrical first and second end pieces interact with a first and a second bore hole which are worked into the components of the internal combustion engine.
A known injection nozzle, DE 44 18 001 A1, is set between a curved suction pipe and a flange connected to a cylinder head. Here, the injection nozzle is connected to the cylinder head as a pre-assembled unit.
In DE 28 29 057 A1 (corresponding to U.S. Pat. No. 4,295,452), injection valves are treated and inserted, on the one hand, into a suction equipment with the first end pieces, and on the other hand, by way of screws, connected to a fuel distributing pipe with the second end pieces.
One goal of the invention is to create a fixing device for an injection nozzle, which on the one hand, is leakproof even at relatively high injection pressures, and on the other, is easy to mount.
According to the invention, at least this goal is solved by incorporating a clamping device which acts upon a nozzle holder body of the injection nozzle, the clamping device keeping in place a first end piece of the nozle holder in a first bore hole of a cylinder head of the internal combustion engine with a defined prestress that acts in an axial direction of the injection nozzle, against which a second end piece of the nozzle holder, preferably with the help of a reduction sleeve, works together with the second bore hole of an intake arrangement.
The advantages of the invention that are mainly achieved are seen in the clamping device that keeps the injection nozzle in place with a defined prestress acting in an axial direction, on account of which the system pressure is taken into account, particularly in direct fuel injection for internal combustion engines of the Otto design, and special screws for each injection nozzle can be eliminated. The reduction sleeve also ensures that the manufacturing tolerances that constantly appear are not damaging to the connecting function of the injection nozzle. With the metallic clamping sleeve, which is easy to produce, a targeted prestress, aimed towards the cylinder head, can be effected also, thanks to the shock absorber. It is also possible for the reduction sleeve to be pre-assembled in a simple manner through the inward formations and the recesses between the clamping sleeve and reduction sleeve or the extension of the clamping sleeve and the wall section of the suction pipe equipment. The assembly of the injection nozzle itself is only a simple introductory process.